Heck Reactions without Salt Formation: Aromatic Carboxylic Anhydrides as Arylating Agents

Environmentally benign and economical production of arylated olefins can be achieved by a new variant of the Heck reaction in which no halogen salts are formed. The trick is the use of aromatic carboxylic anhydrides 1 as arylating agents. With halide-activated palladium chloride as catalyst, which requires no phosphane ligands, the olefins 2 can be prepared according to Equation (a) in good yields.